Protection of the skin from the deleterious effects of ultraviolet light (UV) exposure and other radiation sources prevents the deterioration in the appearance and elasto-mechanical properties of the skin that accompany long-term exposure. The perceived enhanced physical appearance of the skin provided acutely by suntanning is unfortunately offset by the chronic structural deterioration of the skin often leading over time to adversely-perceived skin pigmentation and wrinkling, as well as dysproliferative changes in the skin leading to neoplasia including basal cell and squamous cell carcinoma, and melanoma. It is well known that chronic exposure to the sun results in a deeply grooved and thickened skin, undesirable attributes for which prophylactic and treatment modalities are sought by susceptible individuals. In short, sunlight prematurely ages the skin.
An acute effect of UV damage to the skin is manifest by the necrosis of keratinocytes resulting in the appearance of dyskeratotic cells within the epidermis known as sunburn cells (Daniels et al., 1961, J. Invest. Dermatol. 37:351-7; Gilchrest et al., 1981, J. Amer. Acad. Dermatol. 5:411-22). In addition to UV exposure, numerous other sources of damage to the skin occur in the environment, including exposure to chemicals including airborne industrial and other pollutants, ionizing radiation, among others. Means to protect the aforementioned sequelae of such exposure is highly desirable to prevent the premature aging of the skin.
Certain agents have been shown to reduce the number of sunburn cells after exposure to UV radiation, among them .alpha.-tocopherol (Ritter et al., 1997, Plast. Reconstr. Surg. 100:973-80) and zinc (Record et al., 1996, Biol. Trace Elem. Res. 53:19-25). Such agents offer protection to the skin from the deleterious effects of UV radiation.
It is toward the development of an effective composition for protecting the skin from such damage and prevent premature skin aging that the present application is directed.
The citation of any reference herein should not be construed as an admission that such reference is available as "Prior Art" to the instant application.